Self-propelled Janus particles in a ratchet: Numerical simulations

TL;DR

This study uses numerical simulations to explore how self-propelled Janus particles move in asymmetric channels, revealing their potential for efficient rectification and autonomous pumping compared to traditional thermal ratchets.

Contribution

It demonstrates that Janus particles exhibit significantly stronger ratcheting effects and can induce passive particle transport with minimal active particle addition.

Findings

Janus particles show enhanced rectification in asymmetric channels.

Active Brownian motion leads to strong ratcheting effects.

Passive particle pumping can be achieved with few Janus particles.

Abstract

Brownian transport of self-propelled overdamped microswimmers (like Janus particles) in a two-dimensional periodically compartmentalized channel is numerically investigated for different compartment geometries, boundary collisional dynamics, and particle rotational diffusion. The resulting time-correlated active Brownian motion is subject to rectification in the presence of spatial asymmetry. We prove that ratcheting of Janus particles can be orders of magnitude stronger than for ordinary thermal potential ratchets and thus experimentally accessible. In particular, autonomous pumping of a large mixture of passive particles can be induced by just adding a small fraction of Janus particles.